Severely detached air cell with live chick

I set shipped Silkie eggs, all with detached air cells, and set them upright in a carton. Most are not viable on day 11, but one egg with a severely detached air cell has a live chick. The air cell is so displaced that it is on the side of the upright egg, not at all at either end. If this chick survives, I will no doubt have to perform some sort of epic intervention to help the chick out. I haven't any idea what or how to do such a major assist. I'd like to have a plan, ahead of time, if this chick continues to thrive.
Can anyone instruct me as to what I should do for assisted hatching on day 21-22? Thank you VERY much!